玻碳电极电化学活化的原位FTIR反射光谱研究

用电化学原位FTIR反射光谱法研究了玻碳电极电化学活化过程中表面含氧功能团的生成及其表面过程。结果表明,该电极在高电位下氧化时生成了表面含氧功能团,并有一部分进一步氧化成CO_2,表面类醌基在随后的循环伏安扫描过程中部分转化成酚基,最终形成稳定的表面氧化还原对。表面类醌基同羟基之间存在强的氢键相互作用。

In-Situ FTIR Reflective Spectroscopic Study of Electrochemical Activation of Glassy Carbon Electrode

In-situ FTIR reflective spectrometry was used to study the formation and the changes of oxygen-containing functional groups on the GC electrode surface during its electrochemical activation. The surface functional groups were formed during the high-potential oxidation of GC electrode, some of which were further oxidized to CO2. Parts of the quinone-like groups were reduced during the cyclic voltammetric process thereafter, and stable surface redox couples were formed at the end. In the differential FTIR reflective spectra in these cycling processes appeared positive peaks at 1669 cm-1 and 1690 cm-1, corresponding to quinone-like groups and a wide negative peak at 1590 cm-1, corresponding to the stretching vibration of carboxylic anion and aromatic ring. The potential difference spectra showed a pair of bipolar peaks at 1705 cm-1 and 1750 cm-1 and peaks at 1605 cm-1 and 1580 cm-1. These results are explained by supposing hydrogen-bonding between quinone-like groups and carboxylic groups and the chemical and electrochemical processes of the surface functional groups.